Gum Arabic: A promising candidate for the construction of physical hydrogels exhibiting highly stretchable, self-healing and tensility reinforcing performances

The preparation of tough and healable hydrogels in one step remains a big challenge throughout the field of hydrogel methodology. Herein, we fabricated a series of Poly(N,N-dimethyl acrylamide)-TiO2-gum arabic (PDMAA-TiO2-GA) hybrid hydrogels by simply introducing nanoparticles TiO2 and vinyl-modified gum arabic (GMAGA) into polymer networks. Without complicate molecular design and post-treating process, the hydrogel molding process was simple and effective. The hydrogel exhibited highly stretchable, self-healing and tensility reinforcing performances with the optimized compositions of 30% DMAA, 0.6% GMAGA and 0.13% TiO2. The maximum elongation of the hydrogel after self-healing recover could reach nearly 700% after only 20 min healing time. The hydrogel could ensure 20 times continuous compressive or tensile tests without obvious deformation. Amazing was the significantly enhanced tensile modulus from 5 kPa to 40 kPa after 20 stretch-release cycles. The facile preparation and fascinating tensility reinforcing performance benefit the potential application of the carbohydrate GA in hydrogels.